Citations

Background —Although prompt treatment is a cornerstone of the management of acute myocardial infarction (AMI), prior studies have shown that one fourth of AMI patients arrive at the hospital >6 hours after symptom onset. It would be valuable to identify individuals at highest risk for late arrival, but predisposing factors have yet to be fully characterized. Methods and Results —Data from the Cooperative Cardiovascular Project, involving Medicare beneficiaries aged >65 years hospitalized between January 1994 and February 1996 with confirmed AMI, were used to identify patients who presented “late” (≥6 hours after symptom onset). Patient characteristics were tested for associations with late presentation by use of backward stepwise logistic regression. Among 102 339 subjects, 29.4% arrived late. Significant predictors of late arrival (odds ratio, 95% CI) included diabetes (1.11, 1.07 to 1.14) and a history of angina (1.32, 1.28 to 1.35), whereas prior MI (0.82, 0.79 to 0.85), prior angioplasty (0.80, 0.75 to 0.85), prior bypass surgery (0.93, 0.89 to 0.98), and cardiac arrest (0.52, 0.46 to 0.58) predicted early presentation. Additionally, initial evaluation at an outpatient clinic (2.63, 2.51 to 2.75) and daytime presentation (1.67, 1.59 to 1.72) predicted late arrival. Finally, female sex, black race, and poverty, which were evaluated with an 8-level race–sex–socioeconomic status interaction term, were also risk factors for delay. Conclusions —Delayed hospital presentation is a common problem among Medicare beneficiaries with AMI. Factors associated with delay include not only clinical and logistical issues but also race, sex, and socioeconomic characteristics. Education efforts designed to hasten AMI treatment should be directed at individuals with risk factors for late arrival.

Background —The prognostic value of treadmill exercise testing (TMET) has been studied in selected populations. The generalizability of these data to different populations and to women is uncertain. Methods and Results —A retrospective, population-based cohort study of all persons (1452 men and 741 women) who underwent TMET in years 1987 to 1989 in Olmsted County, Minnesota, was undertaken. Individuals were followed up for all-cause mortality and cardiac events (cardiac deaths, nonfatal myocardial infarction, or congestive heart failure). Sex-specific analyses were performed to determine whether the predictors of outcome and the magnitude of the associations were similar in both sexes. In men, 77 deaths and 106 cardiac events occurred during 8956 person-years of observation; in women, 46 deaths and 54 cardiac events occurred during 4801 person-years of follow-up. Exercise-induced angina, ECG changes, and workload achieved on the TMET were strongly associated with all-cause mortality and cardiac events in both sexes, and the strength of the association was similar. After adjustment, workload was the only TMET variable associated with outcome. A higher workload was associated with a reduction in the risk of cardiac events and of all-cause mortality; the protective effect of exercise capacity was strong and was similar in both sexes. Conclusions —In this population-based cohort, exercise capacity was the TMET variable that exhibited the strongest association with all-cause mortality and cardiac events. This protective effect of exercise capacity was observed in both sexes.

Background 99m Tc sestamibi is a recently developed radioisotope that has been used to measure myocardium at risk and infarct size. The relation between these measurements and subsequent patient outcome has not yet been demonstrated. Methods and Results Two hundred seventy-four consecutive patients with acute myocardial infarction underwent tomographic 99m Tc sestamibi imaging on arrival at the hospital (to measure myocardium at risk before reperfusion therapy) and at hospital discharge (to measure the amount of salvaged myocardium and final infarct size). Defect size on the sestamibi images was quantified using a threshold value of 60% of peak counts from the circumferential count profile curves generated for five representative slices of the left ventricle. Patients were followed after hospital discharge to evaluate the association between final infarct size and subsequent mortality. The median defect size measured was 27% of the left ventricle at presentation to the hospital (range, 0% to 77%) and was 12% of the left ventricle at hospital discharge (range, 0% to 68%). Almost one half of the patients had a final infarct size of ≤10%. The median amount of myocardium salvaged was 9% (range, −31% to 75%). During a median duration of follow-up of 12 months, there were 10 deaths (7 cardiac and 3 noncardiac) and 1 resuscitated out-of-hospital cardiac arrest. There was a significant association between infarct size and overall mortality (χ 2 =8.66, P =.003) and cardiac mortality (χ 2 =11.89, P <.001). Two-year mortality was 7% for patients whose infarct size was ≥12% versus 0% for patients whose infarct size was <12%. There also was a significant association between myocardium at risk and cardiac mortality (χ 2 =6.87, P =.009). There was no association between myocardium at risk and overall mortality or between amount of myocardium salvaged and either overall mortality or cardiac mortality. Conclusions Larger infarct size measured by 99m Tc sestamibi imaging after acute myocardial infarction is associated with increased mortality risk during short-term follow-up.

Background Women who undergo coronary angioplasty have a higher in-hospital mortality than men, although much of this difference can be accounted for by their poorer clinical characteristics at the time of their procedures. However, whether or not there are important long-term differences in outcome between women and men after coronary angioplasty is not clear. Methods and Results A retrospective analysis was performed of 3027 consecutive patients (824 women and 2203 men) who underwent successful angioplasty and who have been followed continuously for a mean of 5.5 years (range, 0.5 to 14 years). Follow-up is 100% complete. Event-free survival was assessed by the Kaplan-Meier method, and clinical end points were also examined by Cox proportional-hazards models to account for important baseline differences when appropriate. There was a trend toward lower survival among women during follow-up, but this was not significant ( P =.06). The relative risk of death among women compared with men after adjustment for baseline differences was 0.94 (CI, 0.76 to 1.15; P =NS). No significant sex differences in occurrence of Q-wave myocardial infarction were observed. Women were less likely to remain free of angina after 10 years (34% versus 37%, respectively; P =.008), but after adjustment for baseline differences, this difference was not significant (relative risk of angina, 1.07; CI, 0.95 to 1.21). Women tended to have less coronary artery bypass surgery performed during follow-up ( P =.06); adjusting for baseline differences made this difference more significant (relative risk, 0.79; CI, 0.64 to 0.96; P =.02). Among patients who were not treated in the setting of acute infarction, no sex differences in survival and freedom from myocardial infarction were noted. Conclusions After successful coronary angioplasty, the long-term prognosis for women is excellent and is similar to that observed in men. Risk-adjusted survival did not differ significantly between the sexes, but less frequent use of subsequent surgical revascularization was observed in women.

Background Among patients with combined coronary artery and peripheral vascular disease, long-term benefits of surgical therapy compared with medical therapy for coronary artery disease are unknown. Methods and Results Using prospectively collected data from the Coronary Artery Surgery Study registry, we performed a retrospective cohort analysis of 1834 patients (mean age, 56 years; 20% women) with both coronary artery and peripheral vascular disease and evaluated their long-term outcomes. Of these patients, 986 received (nonrandomly) coronary artery bypass graft surgery, and 848 were treated medically. Perioperative mortality was 4.2% (2.9% in the absence of peripheral vascular disease; P =.02). In a mean follow-up period of 10.4 years, 1100 deaths occurred (80% due to cardiovascular causes). For the surgical group, 4-, 8-, 12-, and 16-year estimated probabilities of survival were 88%, 72%, 55%, and 41%, respectively, and 73%, 57%, 44%, and 34%, respectively, for the medical group ( P <.0001). Multivariate analysis demonstrated that type of therapy was independently associated with survival ( P =.0001; χ 2 =15.34). Subgroup analysis suggested that benefits of surgical treatment on survival were limited to patients with three-vessel coronary artery disease and were inversely related to ejection fraction. Survival free of death or myocardial infarction was also significantly better among the surgical group. Type of therapy was significantly associated with occurrence of late events ( P =.01; χ 2 =6.55). Subgroup analysis again demonstrated that beneficial effects of surgery were limited to patients with three-vessel coronary artery disease and were inversely related to ejection fraction. Conclusions Surgical treatment provides long-term benefit for certain subgroups of patients with combined coronary artery and peripheral arterial vascular disease.

BACKGROUND Although the technical success rate of coronary angioplasty in the elderly in high, very old patients have increased risk of procedure-related death and late recurrence of severe angina. We proposed to determine baseline variables that predict early and intermediate-term failure of percutaneous transluminal coronary angioplasty (PTCA) in patients more than 65 so we could effectively stratify risk. METHODS AND RESULTS We studied 982 patients at least 65 years old who had urgent or elective PTCA (1980 through 1990). Follow-up (mean, 25 months) was obtained for all patients. Multiple baseline variables were analyzed with univariate and multivariate logistic regression to select independent ones to fit predictive models for in-hospital death or myocardial infarction (overall rate, 6.3%), total in-hospital adverse outcome (overall rate, 18.7%), cumulative survival free of myocardial infarction (overall rate, 15% at 3 years), and cumulative survival free of late nonfatal myocardial infarction, bypass surgery, repeat PTCA, or recurrent severe angina (overall rate, 47% at 3 years). The most heavily weighted parameter in the probability regression equation for each end point was the number of diseased coronary artery segments with at least 70% stenosis. Advanced age was less important. The number of concomitant medical illnesses was predictive of late outcome but not early in-hospital events. Lowest risk quintile versus highest risk quintile event rate was 2.9% versus 14% for acute myocardial infarction or death and 17.2% versus 29% for cumulative in-hospital events. For posthospital events at 3 years' follow-up, lowest risk quintile death or myocardial infarction rate was 4% versus 33% for highest risk quintile. For cumulative late adverse events at 3 years, the event rate was 28% versus 63% for the highest risk quintile. CONCLUSIONS These results stratify patients at high and low risk of early and intermediate-term success after PTCA and identify elderly patients in whom PTCA is most appropriate.

BACKGROUND In acute myocardial infarction, residual flow to the infarct zone either through antegrade flow in the infarct-related coronary artery or collateral flow from the non-infarct-related arteries is often present before reperfusion therapy. The purpose of this study was to assess the influence of antegrade flow in the infarct-related artery and/or collateral flow to the infarct zone before successful direct angioplasty on infarct size and myocardial salvage in patients with acute evolving myocardial infarction. METHODS AND RESULTS Sixty patients with acute evolving myocardial infarction underwent direct successful angioplasty without prior thrombolytic therapy. The myocardium at risk of infarction, the final infarct size, and myocardial salvage were measured by tomographic perfusion imaging with 99mTc sestamibi. Antegrade flow in the infarct-related artery before intervention was graded according to the Thrombolysis in Myocardial Infarction (TIMI) study group classification. Collateral flow to the infarct zone before angioplasty was also graded (0 through 3, 0 being no collateral flow). The presence of even minimal antegrade flow before angioplasty (TIMI grade 1) in the infarct-related artery compared with absent flow was associated with a significant reduction in final infarct size (9 +/- 17% versus 23 +/- 19% of left ventricle, P = .02) and a significant increase in myocardial salvage (23 +/- 16% versus 14 +/- 13% of left ventricle, P = .05) after angioplasty. When antegrade flow in the infarct-related artery was absent before angioplasty, the presence of collateral flow before angioplasty resulted in a significantly smaller final infarct size (P = .01) and more myocardial salvage (P = .05) after angioplasty. Both antegrade infarct-related artery flow and collateral flow to the infarct zone had significant independent ability to predict infarct size after angioplasty. When collateral grade and TIMI grade were added to provide an estimate of residual flow, a model including residual flow, myocardium at risk, and the interaction of residual flow and infarct site explained 83% of the variability in infarct size after angioplasty. CONCLUSIONS The presence of antegrade flow in the infarct-related artery and/or collateral flow to the infarct zone before direct angioplasty in acute evolving infarction results in a smaller infarct size after direct successful angioplasty.

BACKGROUND Complete revascularization after coronary artery bypass surgery is a logical goal and improves symptomatic outcome and survival. However, the impact of complete revascularization in patients with three-vessel coronary disease with varying severities of angina and left ventricular dysfunction has not been clearly defined. METHODS AND RESULTS The study was performed as a retrospective analysis of 3,372 nonrandomized surgical patients from the Coronary Artery Surgery Study (CASS) Registry who had three-vessel coronary disease. Group 1 (894 patients) had class I or II angina (Canadian Cardiovascular Society criteria) and group 2 (2,478 patients) had class III or IV angina. In group 1, adjusted cumulative 4-year survivals according to the number of vessels bypassed were 85% (one vessel), 94% (two vessels), 96% (three vessels), and 96% (more than three vessels) (log rank, p = 0.022). Adjusted event-free survival (death, myocardial infarction, definite angina, or reoperation) was not influenced by the number of vessels bypassed, nor was the anginal status among patients remaining alive after 5 years. In group 2, adjusted cumulative 5-year survivals were 78% (one vessel), 85% (two vessels), 90% (three vessels), and 87% (more than three vessels) (log rank, p = 0.074). Adjusted event-free survivals after 6 years were 23% (one vessel), 23% (two vessels), 29% (three vessels), and 31% (more than three vessels) (p = 0.025); at 5 years, those with more complete revascularization were more likely to be asymptomatic or free of severe angina. Among group 2 patients with ejection fractions less than 0.35, 6-year survival was 69% for those with grafts to three or more vessels versus 45% for those with grafts to two vessels (p = 0.04). Placing grafts to three or more vessels was independently associated with improved survival and event-free survival in group 2 but not group 1 patients. The case-fatality rates among 529 patients experiencing a myocardial infarction during follow-up was significantly higher for patients with less complete revascularization. CONCLUSIONS Complete revascularization (grafts to three or more vessels) in patients with three-vessel coronary disease appears to most benefit those with severe angina and left ventricular dysfunction.

Background Hypertrophic cardiomyopathy is a disease entity characterized by marked heterogeneity in morphology and natural history. Most of our knowledge of the natural history of this disorder derives from the study of hospital-based populations and is influenced by referral bias. Therefore, this population-based study was undertaken to examine the natural history of hypertrophic cardiomyopathy among unselected residents of Olmsted County, Minnesota. Methods and Results Patients with hypertrophic cardiomyopathy, confirmed by echocardiography, were identified by use of the resources of the Rochester Epidemiology Project. Patients with the echocardiographic features of hypertrophic cardiomyopathy but with long-standing hypertension requiring drug therapy were categorized as having hypertensive hypertrophic cardiomyopathy. Baseline clinical details and follow-up events were obtained by retrospective chart review. Thirty-seven patients were diagnosed with hypertrophic cardiomyopathy and 24 with hypertensive hypertrophic cardiomyopathy. Eight additional patients were first diagnosed at autopsy. The mean age of the 37 patients with hypertrophic cardiomyopathy was 59±20 years (range, 1 week to 92 years); the mean ventricular septal thickness was 17.5±3 mm. Follow-up was obtained for a median of 7.7 years (range, 45 days to 17.2 years). The 1- and 5-year survival rates were 95% and 92%, respectively; these rates did not differ from those of an age- and sex-matched population ( P =NS). The annual risk of cardiac death was 0.7%. The mean age of patients with hypertensive hypertrophic cardiomyopathy was 79±8 years (range, 62 to 91 years), and the mean ventricular septal thickness was 19±2.5 mm. Follow-up was obtained for a median of 2.8 years (range, 4 days to 16.7 years). The 1- and 5-year survival rates were 75% and 43%, respectively, which differed sharply from the expected rates of 94% and 70% ( P =.0028). The annual risk of cardiac death was 5%. Atrial fibrillation and evidence for myocardial infarction on ECG, use of digoxin and diuretics, and a high New York Heart Association functional class at presentation were all associated with decreased survival by multivariate analysis for both groups combined. A history of myocardial infarction, atrial fibrillation, and mitral annular calcification at presentation were associated with cardiac death. Conclusions Hypertrophic cardiomyopathy is a more benign disease than previously reported from tertiary referral centers. Patients assessed as having hypertensive hypertrophic cardiomyopathy represent a subset at higher risk for cardiac and noncardiac death, with an overall decreased survival rate.